Add AVIF image support via libavif

Add an AVIF codec (LLImageAVIF) to llimage backed by libavif with
dav1d (decode) and aom (encode), and wire it into the image upload
and save/snapshot paths, mirroring the existing WebP integration.

- llimage: IMG_CODEC_AVIF and LLImageAVIF (lossy quality-based encode,
  8-bit RGB/RGBA decode with vertical flip); extension, MIME, and
  dimensions-info registration
- build: libavif[aom,dav1d] vcpkg dependency and AVIF.cmake module
- upload: file picker load filters, IMAGE_EXTENSIONS, local bitmaps
- save: FFSAVE_AVIF, snapshot format (combo box, encode switches,
  quality slider) and texture save-as

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: RyeMutt

.github/workflows/build.yaml

@@ -215,7 +215,7 @@ jobs:
             libthai-dev libtool libudev-dev libunwind-dev liburing-dev libvlc-dev libwayland-dev \
             libx11-dev libxcursor-dev libxext-dev libxfixes-dev libxft-dev libxi-dev libxinerama-dev \
             libxkbcommon-dev libxrandr-dev libxss-dev libxtst-dev linux-libc-dev mono-complete \
-            ninja-build pkgconf tar tex-common texinfo unzip zip
+            nasm ninja-build pkgconf tar tex-common texinfo unzip zip
 
           sudo locale-gen en_US.UTF-8
           sudo locale-gen en_GB.UTF-8
@@ -232,7 +232,7 @@ jobs:
       - name: macOS Homebrew Dependency Install
         if: runner.os == 'macOS'
         run: |
-          brew install autoconf autoconf-archive automake libtool mono unzip zip
+          brew install autoconf autoconf-archive automake libtool mono nasm unzip zip
 
       - name: Checkout code
         uses: actions/checkout@v6

indra/CMakeLists.txt

@@ -243,6 +243,7 @@ endif ()
 
 # Declare All Dependency Includes
 include(APR)
+include(AVIF)
 include(Boost)
 include(bugsplat)
 include(CEFPlugin)

indra/cmake/AVIF.cmake

@@ -0,0 +1,6 @@
+# -*- cmake -*-
+include_guard()
+add_library(ll::libavif INTERFACE IMPORTED)
+
+find_package(libavif CONFIG REQUIRED)
+target_link_libraries(ll::libavif INTERFACE avif)

indra/cmake/CMakeLists.txt

@@ -3,6 +3,7 @@
 set(cmake_SOURCE_FILES
         00-Common.cmake
         APR.cmake
+        AVIF.cmake
         Boost.cmake
         BootstrapVcpkg.cmake
         bugsplat.cmake

indra/llimage/CMakeLists.txt

@@ -14,6 +14,7 @@ target_sources(llimage
     llimagepng.cpp
     llimagetga.cpp
     llimagewebp.cpp
+    llimageavif.cpp
     llimageworker.cpp
     llpngwrapper.cpp
     )
@@ -32,6 +33,7 @@ target_sources(llimage
     llimagepng.h
     llimagetga.h
     llimagewebp.h
+    llimageavif.h
     llimageworker.h
     llmapimagetype.h
     llpngwrapper.h
@@ -52,6 +54,7 @@ target_link_libraries(llimage
     llmath
     llcommon
     ll::libwebp
+    ll::libavif
     ll::libpng
     ll::libjpeg
     )

indra/llimage/llimage.cpp

@@ -39,6 +39,7 @@
 #include "llimagejpeg.h"
 #include "llimagepng.h"
 #include "llimagewebp.h"
+#include "llimageavif.h"
 #include "llimagedxt.h"
 #include "llmemory.h"
 
@@ -2049,7 +2050,8 @@ file_extensions[] =
     { "mip", IMG_CODEC_DXT },
     { "dxt", IMG_CODEC_DXT },
     { "png", IMG_CODEC_PNG },
-    { "webp", IMG_CODEC_WEBP }
+    { "webp", IMG_CODEC_WEBP },
+    { "avif", IMG_CODEC_AVIF }
 };
 
 static struct
@@ -2069,7 +2071,8 @@ wide_file_extensions[] =
     { L"mip", IMG_CODEC_DXT },
     { L"dxt", IMG_CODEC_DXT },
     { L"png", IMG_CODEC_PNG },
-    { L"webp", IMG_CODEC_WEBP }
+    { L"webp", IMG_CODEC_WEBP },
+    { L"avif", IMG_CODEC_AVIF }
 };
 #define NUM_FILE_EXTENSIONS LL_ARRAY_SIZE(file_extensions)
 #if 0
@@ -2270,6 +2273,9 @@ LLImageFormatted* LLImageFormatted::createFromType(S8 codec)
       case IMG_CODEC_WEBP:
         image = new LLImageWebP();
         break;
+      case IMG_CODEC_AVIF:
+        image = new LLImageAVIF();
+        break;
       case IMG_CODEC_J2C:
         image = new LLImageJ2C();
         break;
@@ -2314,6 +2320,10 @@ S8 LLImageFormatted::getCodecFromMimeType(std::string_view mimetype)
     {
         return IMG_CODEC_WEBP;
     }
+    else if (mimetype == "image/avif")
+    {
+        return IMG_CODEC_AVIF;
+    }
     return IMG_CODEC_INVALID;
 }
 

indra/llimage/llimage.h

@@ -85,7 +85,8 @@ typedef enum e_image_codec
     IMG_CODEC_DXT  = 6,
     IMG_CODEC_PNG  = 7,
     IMG_CODEC_WEBP = 8,
-    IMG_CODEC_EOF  = 9
+    IMG_CODEC_AVIF = 9,
+    IMG_CODEC_EOF  = 10
 } EImageCodec;
 
 //============================================================================